#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<assert.h>
int my_strlen(const char* str)
{
	int len = 0;
    assert(str != NULL);
	while(*str != '\0')
	{
	    str++;
		len++;
	}
	return len;
}
int main()
{
	int len = 0;
    char arr[] = "abcdef";
	len = my_strlen(arr);
	printf("%d\n",len);
	return 0;
}